Question

ОЧЕНЬ СРОЧНО! помогите:с

21/sin^2 28 + cos^2 208

Answer 1

$\frac{21}{sin^228+cos^2(180 +28)} = \frac{21}{sin^228+cos^2( \pi +28)}= \frac{21}{sin^228+cos^228}= \frac{21}{1}=21$